A bodhisattva is born as a hare and sees the full moon, brightly lit in the sky
He realizes it is the day before the 15th day of the month when one must not consume any food before feeding a guest first. He is very upset that he has no food good enough to offer to a guest, so as a hare, he decides he will offer himself as a meal to his future guests.
The king of gods; Sakka, is wanders through the forest looking for the hare after being baffled by hearing his selfless and saddening resolve.
After meeting Sakka, the hare lights a fire and offers himself to the king, throwing himself into the flames.
The king is stunned, but appreciates the hares sacrifice, thus deciding to honour him by drawing an image of the hare on the moon.